Light-sensitive material



May 4, 1943 w. MICHAELls 2,318,007

' Y LIGHT-SENS ITIVE MATERIAL Filed Jan. s. 1940 rea sena/five.

Sme/whom Patented May 4, 1943 LIGHT-SENSITIVE MATERIAL Walter Michaelis, Brussels-Forest, Belgium, as-

signor, by mesne assignments; to Chromogen, incorporated, a corporation of Nevada Application January 8, 1940, Serial No. 312,983 In Great Britain .l'anuary l0, i939 Claims.

The present invention relates to a process for producing photographic dye `images by local removal of the dye from homogenously colored layers that contain photographic silver images produced in silver halide emulsion layers colored complementarily to the sensitivity ofthe layer. The process comprises the local removal of the dye from a multilayer material, the layers of which are carried by a transparent support, at least one layer containing identical silver images produced by exposure of the layer from both sides thereof.

The invention further relates to a multilayer light-sensitive material comprising several co1- ored light-sensitive layers for carrying out the process and for producing multicolor photographs by direct exposure in an appropriate camera or by printing.

A great number of methods have already been described for producing color-photographic materials ith a number of emulsion layers dyed to diierent colors with dyes used in the production of the final color image, the emulsion layers being sensitive to light of dierent colors.l The individual layers are either sensitized for light rays that are absorbed by the color With which the layer is dyed, or the layers are sensitized for light rays of a color not absorbed by the color of the layer. Materials of the latter type do not permit one to obtain color-photographs true to nature from the material exposed in the camera. On the other hand, the materials of the firstmentioned 'group when treated with the dyedestroying solutions that destroy the dyes Where silver is present have hitherto yielded pictures that are not satisfactory, the reasons being as follows:

The dye present in the layer absorbs the light rays of the color for which the emulsion has been sensitized and if the dye possesses the concentration requisite for the production of intensely colored pictures, its absorption limitsthe extures obtained are ilat and of unsatisfactory appearance.

In the accompanying drawing I have shown a diagrammatic cross sectional illustration of a typical multilayer material made in accordance with the present invention. J

In carrying out the present invention a multilayer material such as shown in the drawing is used, the layers orwhich are dyed complementary to the sensitivity of the layer and the material is adapted to be exposedfrom both sides. By permitting the light to penetrate from both .posure .Con-the surface Vof the layers-'The pic-'fwVv `for different lengths of time.

sides into such a layer which is dyed with a concentration sufficient to produce an intensely colored image), one can'produce therein two exactly registered images that reinforce each other and permit one to process the layer to obtain a satisfactory color image.

Exorcism-Referring now to the drawing, one side of a transparent support is coated with a magenta-dyed green-sensitive silver halide emulsion layer I and superimposed on this layer there is a second yellow-dyed, blue-sensitive layer 2. On theother side of the support, there is coated a red-.sensitive layer 3 dyed bluegreen and superposed on this is coated a yellowdyed blue-sensitive layer 4. The whole -material thus consists of a support and :four layers in three basic colors. one of which, i. e. yellow is present in the opposite surface layers Z and i on both sides of the material. The followingdyes may be employed: for the magenta layer Benzopurpurine 10 B (Schultz Farbstoitabellen Leipzig 1931, '7th ed., vol. 1, No. 489)l in a concentration of .4 grm. per sq., m.; for the bluegreen layer Pontamine Sky' Blue 6 BX (Schultz. loc. cit., No. 510) in a concentration of .5 grm. per sq. m. and for each yellow dyed layer Chrysophenine G `(Schultz loc. cit., No. 726) in a concentration of .5 grm. per sq. m. Exposure is effected in a camera provided with a system of Amirrors that permits of coincident images being taken from both sides. Cameras of this type are already known, for example from Brewsters U. S. Patent No. 1.253,13'7 and therefore there is no need to describe them in detail.

The material may also be. employed as a printing material in order to obtain multicolor pictures by printing. To this end lthe material is exposed to the multicolor master image,` for ex- Va. colored printing light composed of blue light,

green light and red light. These light compo- .nents may be allowed toact simultaneously or may be used in successive printing operations or After exposure, the multilayer film is developed in the usual manner-and thereafter the dyes in the layers are destroyed locally, dependingv layers. Positive prints are obtained direct from positive master images if the dye is destroyed at the places where silver has been formed by 'the development, for example by a process of the kind on the silver i bleached with the aid of a metallic silver image,

two of said emulsion layers being sensitive to b1ue` light and colored yellow, the third being colored magenta and sensitive to green light, the

fourth being colored blue-green and sensitive to red light, said magenta colored layer and said blue-green colored layer being arranged between said two yellow colored layers, the arrangement and coloring of the layers forming said material being such that the layers superposed with respect tosaid magenta colored layer and said blue-green colored layer are transmittant for both freen and red `light introduced from either side of said material, and the dyes in said magenta colored layer and said blue-green colored layer being sufficient in concentration for natural reproduction of a multicolor Iimage when taken together with the dye in said two yellow colored layers.

2. A light sensitive material for color photography comprising a plurality of superposed silver halide layers each predominantly sensitive to a different portion of the visible spectrum and diffusely dyed complementarily to their respective sensitivities with dyes which are resistant to ordinary photographic treating solutions but .capable of being bleached with the aid of a meof said layers from the other side oi said material the same part image recorded therein by said first recording to intensify the latent silver image obtained by said first recording, developing said images, and destroying the dyestuff in said layers -in proportion to said developed silver images.

4. The method of making4 multicolor photographic images in a light sensitive material including a plurality' of superposed silver halide layers each predominantly sensitive to a diierent portion oi the visible spectrum and diffusely dyed complementarily to their respective sensitivities with dyes which are resistant to ordinary photographic treating solutions but capable of being .bleached with` the aid of a metallic silver image,

there being a set of said layers whose combined predominant sensitivities are adapted to record the visible spectrum, and a supplementary layer substantially identical in predominant sensitivity and color with one of said set, the layers of said main'ing layers a natural color muticolor image may be produced which comprises, exposing said material from one side to form a color separation image in each of the layers of said set. exposing said material from the other side to form a color separation image in said supplementary layer the same as that formed` in the layer of said set having the same sensitivity and to form in said intermediate layers additional separation images the same as those altallic silver image, there being a set of said layers whose combined predominant sensitivitives are adapted to record the visible spectrum, and a t supplementary layer substantially identical in forming said material being such that the layers superposed with respect to `said intermediate ready formed therein from the other side of said material, developing said images, and destroying the dyestuii in said layers in proportion to said developed silver images.

5. The method of making multicolor photographic images in a light sensitive material including four superposed light sensitive silver halide layers dyed with dyes which are resistant to ordinary photographic treating solutions but capable of being bleached with the aid of a metallic silver image, two of said emulsion layers layers are tranmittant for light to which said intermediate layers are sensitive when said light is introduced from either side lof said material, and the dyes in each of said colored layers being of such a concentration that when taken in combination with the remaining layers a natural color muticolor image may be produced.

y 3. A method of making multicolor photographic images in a material comprising a plurality of superposed silver hailde layers each predominantly sensitive to a dierent predetermined dyed complementarily to their'respective sensitivities with dyes which are resistant to ordinary photographic treating solutions but capable portion of the visible spectrum and diiiusely tion image, which comprises, recording a color,

separationimageineachotsaidlayers'frmn one side of said material. recording in said one being sensitive to blue light and colored yellow, the third being colored magenta and sensitive to green light, the fourth being colored blue-green and sensitive to red light, said magenta colored layer and said blue-green colored layer being arranged between said twoyellow colored layers and the dyes therein being suflicient in concentration for natural .reproduction of a multicolor image when taken together with the dyev in said two yellow colored layers which comprises, exposing said material from one side to form color separation images correspondingto their sensitivity in one ,of said yellow colored layers and in each of said magneta colored and blue-green colored layers, exposing saidmaterial from theother side to iorm a color separation image corresponding to its sensitivity inl the other yellow colored layer and to form'in said magenta colored and in said blue-green colored layers additional separation images the same as those already formed therein from the other side of said material, developing said images, anddestroying WALTER. M ICHAEms. 

